Cushion for sheet-metal presses



. y 6, 1930. F. J. RODE 1,757,738

CUSHION FOR SHEET ME TAL PRESSES Filed Feb. 9, 1?;29 5 Sheets-Sheet 1May 6, 1930. F. J, ROBE 1,757,738

CUSHION FOR SHEET METAL PRESSES Filed Feb. 9, 1929 5 Sheets- Sheet 2 May6, 1930. 4 F,J RODE 1,757,738

CUSHION FOR SHEET METAL PRESSES Filed Feb. 9, 1929 5 Sheets-Sheet 3Patented May 6, 1930 UNITED STATES PATENT; OFFICE" FRIEDRICH J'. RODE,OF CHICAGO, ILLINOIS, ASSIGNOR '10 MARQUETTE T001178: MFG. COMPANY, OFCHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS CUSHION FOR SHEET-METALPRESSES Application filed February 9, 1929. Serial No. 338,817.

This invention relates to improvements in cushioning devices fr,pressesof the character in which the metal is shaped by means of cooperatindies, one of which is reciprocable toward an away from the other, thework being clamped or held by means of a blank or work holding elementthat co-operates with the reciprocable die member, the blank or workholder being resisted in its movement in one direction by a pad, thelatter being resisted by the said cushion, and one of the objects of theinvention is to provide improved means for varying the resistancepressure against which the pad is movable.

A further object is to provide a fluid pressure cushion and fluidpressure. controlled variable resistance pressure creating means againstwhich the pressure pad operates, the variable resistance pressurecreating means comprising a double cushion embodying two separate fluidcontrolled cushion elements, and improved means whereby the pressure inone of said elements may be varied without interfering with the -fluidpressure in the other cushion element.

To the attainment of these ends and the accomplishment of other new anduseful objects as will appear, the invention consists in the features ofnovelty in substantially to the construction, combination andarrangement of the several partshereinaftermore fully described andclaimed and shown in the. accompanying drawings illustrating thisinvention and in which Figure 1 is a view partly in elevation, parta-ndwith parts omitted, showing the position of the parts of the cushionwhen the ram is in a raised position.-

Figure 3 is a view similar to Figure 2,

ram is lowered. r v

I Referring more particularly to vthe drawings the numeral 10 designatesthe supporting base ofa press, 11 uprights, 12 a reciprocable 'forliquid to the cylinder.

ly in section, and partly broken away of a 7 tion, partly 7 in Isection, partly broken' away showing the positionof the parts when theram, 13 a reciprocable die whichco-operates with a die 14, the latterbeing mounted upon the bed of the press.

Beneath the press is arranged a cushion embodying a cylinder 15 mountedupon a suitable support 16, which latter is in turn supported preferablyfrom the bed of the press by .means of hangers 17. Within the cylinder15 is a reciprocable piston 18 to which a piston rod 19 is connected,and the -piston rod in turn is connected with a pressure pad 20upon-which pins or projections 21 rest, and which pins pass through thebed plate and are connected with the blank or work holding element 22. 16

The ram 12 is reciprocable preferably by means of links 23 connectedwith a crank shaft 24 and connected to the shaftis a fly wheel 25. Y

All of the above referred to parts areof the 7 ordinary and well lmownconstruction.

The cylinder 15 is provided with an outlet 26 preferably arrangedadjacent the bottom thereof and communicating with this outlet is avalve casing or chamber 27 which is provided with an opening 28 whichserves as an inlet and an outlet for liquid to and from the cylind r 15, and thecasing 27 is also provided with a opening 29 which serves asan inlet Communicating with the opening 28 is a pipe 30 which receives asupply of liquid 31 rom a container or receptacle 32. A fluid supplypipe33 has communication with the container 32 preferably adjacent thetop thereof and in the pipe 33 isarranged a'pressure regulating valve 34of any desired construction, and a pressure indicating gau'ge' 35. Thefluid enters the container32 above the liquid 31, the height of theliquid being'indi' 90 cated, by an indicator gauge 36, and forces theliquid from the container through the pipe 30 and through the opening 29into'th cylinder 15through the opening- 26:

The opening 29has comm'u'mcation with the pipe 30 and a springcontrolledvalve 37 is provided for closing the opening 29 to preventliquid from flowing-out'of'the cylinder 15. and into the pipe 30, asshowninFigure3, Y

but will open to permit the liquid to-flow from the pipe 30 and intothecylinder 15, as shown in Figure 2.

A valve 38 is provided for controlling the point of communicationbetween the opening 29 and the pipe 30 so that when the valve 38 isunseated as shown in Figure 2, liquid under pressure in the container 32will flow into the cylinder, past the valve 38, through the opening 29to raise the piston 18.

When, however, the valve 38 is seated as shown in Figure 3, liquidcannot flow into the cylinder 15 when the opening 28 is closed.

A valve 39 is provided-for the opening 28 so that when the opening28 isclosed and the piston 18 is lowered, a pressure will be created upon theliquid in the cylinder 15, the tendency of the pressure being to forcethe liquid out of the cylinder back into the container 32. This will beprevented, however, by reason of the fact that the valve 37 will beclosed under such pressure, and the liquid can only flow back into thecontainer 32 through the opening 28 when the valve 39 is unseated.

. one of the wa'lls of each of the cyIinderssuch as from a tank orcontainer 46.

So long as the valve 39 is seated pressure will be built up upon theliquid in the cylinder 15 and when such pressure exceeds the.

pressure by means of which the valve 39 is seated, the valve will beopened under such pressure and the liquid will escape from the cylinderback into the container.

Therefore, in order to vary or control the resistance pressure of theliquid inthe cylinder 15 against which the piston 18 and pres sure pad20 must act to resist the movement of the element 22, means are providedfor varying the pressure exerted upon, the valve 39 to hold the latterseated.

In the present form of the invention such means embodies a pair ofcylinders 4040 which are supported upon ,the casing ofthe valve chamber27. Connected with the va ve 39 is a stem or rod 41 which passes throu h4040 and connected with this .stem are pistons 4l '41 reci'procablerespectively in the cylinders 40-40. These cylinders 40 other. I

A ipe 44. has communication with the cylinder 40 on one side of thepiston 41 and to the pipe 44 is connected a pipe 46 through whichfluidunder any desired pressure is conveyed from any suitable source ofsupply A fluid pressure regulating valve 47 may be providedforcontrolling the pressure of the fluid through the pipe 46, and thepressure indicating gauge 48 may also be provided.

Leading from the pipe 46 adjacent the cylinder 40 is an extension 46which has communication with an opening 46 extending through the head ofthe cylinder 40 to form communication between-said pipe extension 46 andthe cylinderl40 on one side of the head of the cylinder 40 on the sideof the piston 41 opposite to the side on which the pipe44 communicateswith the cylinder 40. This opening 44 serves as an inlet and also anoulet for fluid on one side of the piston 41 in the cylinder 40:Communicating with the opening 44 is a pipe 44 which may be supported bymeans of a suitable bracket 44. Connected with the pipe 44 is a two-wayvalve casing 44 having an opening 44 communicating with the atmosphere.A branch pipe 44 forms communication between the pipe 46 and the valvecasing 44.' Within this valve casing is a three-way valve 44 adapted tobe adjusted by means of a handle 44 so asto form communication betweenthe pipe 46 through the branch 44 (see Figure 3), through the, valvecasing 44, with the pipe 44 so that when the valve 44 is in the positionshown in Figure 3, fluid'from the pipe 44 will flow into the cylinder 40beneath the piston 41 and also through the pipe 44 on the top side ofthe piston 41*" to new tralize the pressure on both sides of the piston.At the same time pressure will flow into the cylinder 40 on the top sideof the piston 41 so that the valve 39 will then be held against its seatonly by the pressure on the piston 41*.

. When, however, the valve 44 assumes the position shown in Figure 2,communication will be established from the pipe 46, throu h the pipe 44,into the cylinder 4O above t e piston 41', and also through theextension '41 to escape. At this time the valve 39 will and 40 are outoffiicommunication with each be held seated by the combined pressure onboth of the pistons 41* and 41". ,f

It will therefore be manifest that by ad-' just-ing the valve 44 theoperation of the valve 39 maybe controlledand the degree of resistancepressure with which the valve 39 is held closed will be "controlled bythe degree of fluid pressure in the cylinders 40 and 40 on the top sidesof the respective pistons 41 and 41 7' In order therefore to vary theresistance pressure exerted upon the valve 39 it is only necessary tovary or control the fluid pressure.

In order to vary the fluid pressure exerted upon the valve 39- to holdit seated, the valve 44 serves as a means whereby the fluid pressure inthe cylinder 40 may be balanced without interfering with the fluidpressure in the .cylinder overcomes the pressure in the cylinders 40 and40 the valve 39 will be unseated and the liquid will fiow through thepipe back into the container 32 assuming that the valve 38 is closed.

After the piston 18 has reached the limit of its lowermost movement andwhen the pressure in the cylinder 15is overcome by the pressure in thecylinders 40*, the valve 39 will be seated and the piston 18 will remainin its lowermost position until the liquid from the container 32 isagain forced.

back into the cylinder 15 through the opening 26. This will occur whenthe valve 38 is open. Assuming the valve 38 to be open as 'shown inFigures 1 and 2, and the valve 39 is closed, it will be manifest thatthe liquid will flow from the pipe 30, past the valve '38, through theopening 29, past the valve 37,

throughthe opening 26, into the cylinder 15 to raise the piston 18.

The admission of the liquid into the cylinder 15 to raise the pistonl8may be controlled at any predetermined point in the cycle of operationof the press, but the valve 38, which controls the return of the piston18, is preferably operated at a time in the cycle of operation of thepress so as to prevent the piston 18 and the pressure pad 20 fromimmediately following the ram and die 13 when the latter start torecede. In other words, so that the piston 18 will be retained for apredetermined period of time at the limit of its lowermost stroke. Thisis accomplished by controlling the operation of the valve 3 8.

In the present form of the invention this valve is controlled from amovable part of the press such as the crank shaft 24 through the mediumof a rod or link 49 which is preferably jointed as at 49 and isconnected to the crank and passes loosely through an arm 50 connectedwith a shaft 5] that is journaled in a suitable bracket 52. On the endof the rod is an adjustable collar 53 with which a portion 54 on thearm50 is adapted to engage.

Connected also with the shaft 51 is another arm 55Qand this arm. isconnected by means of a link 56 with an arm 57 of a bell crank lever,the latter being pivotally supported as at- 58 to a bracket 59. Theother arm 60 of the bell crank lever is connected by means of a link 61to an arm 62 on a rock shaft 63. Connected with the rock shaft 63 is anarm 64 which engages beteween spaced shoulders or collars 65 on the stem66 of the valve 38. A

spring 67 is connected by one end with the arm 62 and is anchored to afixed support by its other end. 'The normal tendency of the spring 67 isto move the valve 38 in a direction to seat the latter.

When pressure is exerted upon the liquid in the cylinder 15 suchpressure will be prevented from acting upon the valve 38 to unseat thelatter by reason of the valve 37 closing under such pressure. The onlyexit under these conditions for the liquid from the cylin-. der 15 isthrough the opening 28, but as this able means may beprovided foraccomplishing this result. A simple and efficient means embodies a pairof arms or fingers68-69 which are secured to the rod 49. The arm 44 ofthe valve 44 is provided with a lateral extension which is arrangedwithin the path of reciprocatory movement of the arms" 68 69. When therod 49 is raised the arm 68 will engage the projection 7 0 and move thevalve 44 in one direction, at a predetermined time in the cycle ofoperation of the press. When the rod 49 is lowered the arm 69 willengage the projection 70 on the arm 44 and move the valve 44 in theopposite direction at another predetermined time in the cycle ofoperation of the press, with the result that the valve 44 will beautomatically shifted during the reciprocatory movement of the rod 49.

. It is thought that the operation of this device will be clearlyunderstood from the foregoing without further explanation.

The valve 38, however, will be unseated by the engagement of theshoulder or collar 53 with the arm 50 at a predetermined time in thecycle of operation of the press, that is after the ram has started toascend,' the collar 53 being adjusted to engage a rock arm.

.67 will cause the arm 50 to follow the collar 53 and will close thevalve 38. The valve 38 will be" closed before the ram reaches the limitof its downward movement, and for this reason the rod 49 slides looselythrough the arm 50. i

While the preferred form of the invention has been herein shown anddescribed, it is to be understood that various changes may be made inthe details of construction and in the combination and arrangement ofthe several parts, within the scope of the claims,-

controlled elements, and means for varying the fluid pressure in one ofsaid elements independently of the other of said elements. 2. In a sheetmetal press a pressure pad, a cushion for rsisting the movement of thepad in one direction, means for creating a variable resistance pressurein said cushion, said means embodying two fluid pressure controlledelements, and means responsive in its operation to the operation of amovable-part of the press for varying the fluid pressure in one of saidelements mdependently of the other of said elements.

' 3. In a sheet metal press a pressure pad, a cushion for resisting themovement of the pad in one direction, means for creating a variableresistance pressure in said cushion,

' said means embodying two fluidpressure controlled elements, and meansfor neutralizing the fluid pressure of one of said elements while thefiuid'pressure of the other of said elements remains active.

4. In a sheet metal press a pressure pad, a cushion for resisting themovement of the pad in one direction, means for creating a variableresistance pressure in said cushion, said means embodying two fluidpressure controlled elements, and means for neutralizing the fluidpressure of one of said elements independently of the other element, thesaid means being also operable to establish a uniform fluid pressureinboth of said elements.

4 5. In a sheet metal press a pressure pad, a cushion for resisting themovement of the pad in one direction, means for creating a vari-' ableresistance pressure in said cushion, said means embodying two fluidcontrolled elements out of communication with each other, means forsupplying fluid under pressure to said elements to create apredetermined pressure in the elements independent of each other, andmeans for varying the fluid pressure of one of said elements while theother of said elements maintains its predetermined pressure.

6. In a sheet metal press a pressure pad, a cushion for resisting themovement of the pad in one direction, means for creating a variableresistance pressure in said cushion. said means embodying two fluidcontrolled elements out of communication with each other, means forsupplying fluid under pressure'to said elements to create apredeterminedpressure in the elements ind'ependent of each other, meansfor supplying fluid under pressure to said elements to createapredetermined pressure in the elements independent of each other, meansrendered elfective at a predetermined time in the cycle of operation ofthe press for varying the fluid pressure of one of said elements whilemaintaining the said predetermined fluid pressure of the other of saidelements, and means whereby the time of operation of the last said meansin the cycle of operation of the press may be varied.

8. In a sheet metal press a pressure pad, means for resisting themovement of the pad in one direction, means for creating a variableresistance pressure to the movement of said pad, the last said meansembodying a pair of cylinder and piston elements, means for supplyingfluid under pressure to said cylinders independently of each other toestablish predetermined fluid pressures in said cylinders, and means forreducing the pressure in one of said cylinders While the saidpredetermined pressure is maintained in the other of said cylinders.

9. In a sheet metal press a pressure pad, means for resisting themovement of the pad in one direction, means for creating a variableresistance pressure to the movement of said pad, the last said meansembodying a pair of cylinder and piston elements, means for supplyingfiuid under pressure to said cylinders independently of each other toestablish predetermined fluid pressures in said cylinders, and meanscontrolled in its action by a movable part of the press for reducing thepressure in one of said cylinders while the said predetermined pressureis maintained in the other said cylinders.

10. In a sheet metal press a pressure pad,

inders for supplying fluid thereto under a predetermined pressure, andmeans for reducmg the pressure-1n one of said cylinders while the fluidis maintained at said predeteri mined pressure in the other of thecylinders. 11. In a sheet metal press a pressure pad,

means for resisting the movement of the pad in one direction, means forcausing said re;

sistance to be variable, the lastsaid means embodying a pair ofcylinders and pistons individual thereto, means for supplying fluidpressure to each of the cylinders on one side of the respective pistons,means for supplying said fluid pressure on the opposite side of one ofsaid pistons to neutralize the fluid ressure on the opposite side of thelast sai piston, and means for controlling the last said means.

12. In a sheet metal press a pressure pad means forresisting themovement of the pad in one direction, means for causing said resistanceto be variable the last said means embodying a pair of cylinders andpistons individual thereto,'means i'or supp ying fluid pressure to eachof the cylinders on one side of the respective. pistons, means forsupplying said fluid pressure. on the opposite side of one of saidpistons to neutralize the fluid pressure on the opposite side of thelast said piston, and means operable at a predeter mined time in thecycle of operation of the press to control the last said means. 13. In asheet metal press a pressure pad means for resistingthe movement of thepad in one direction, means for causing said'resistance to be variable,the last said means embodying a pair of cylinders and pistons individualthereto, means forsupplying fluid 3 pressure toeach of the cylinders onone side of the respective pistons, means for supplying said fluidpressure on the opposite side of one of said pistons to neutralize thefluid pressure on the opposite side of the last said piston, and meansoperable by a movable part of the press for controlling the last saidmeans. I

14. In a sheet metal. press a pressure pad, means for resisting themovement of the pad 40 in one direction, means for causing saidresistance to be variable, the last said means embodying a pair ofcylinders and pistons individual thereto, means for supplying fluidpressure to each of the cylinders on one side of the respective pistons,means for supplying said fluid pressure on the opposite side of one ofsaid pistons to neutralize the fluid pressure on the opposite side ofthe last said piston, and means embodying a two-Way valve device forcontrolling the last recited means. In testimony whereof I have signedmy name to this specification, on this 21st day of January, A. D. 1929.

" FREDRICH J. RODE.

